@article { ISI:000230879600018, title = {Stereoselectivity ratios in a simple Diels-Alder reaction in aqueous salt solutions of alcohols}, journal = {Tetrahedron}, volume = {61}, number = {33}, year = {2005}, month = {AUG}, pages = {8025-8030}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

This is the first exhaustive report on the variation of stereoselectivity ratios for a simple Diels-Alder reaction between cyclopentadiene and methyl acrylate. The reaction was carried out in aqueous mixtures of methanol, ethanol, propan-1-ol and butan-1-ol in presence of LiClO4, LiCl, NaCl, KCl, CaCl2 and MgCl2. The endo sterecisomer decreases with the increase in carbon chain length of the alcohol. However, LiClO4, a salting-in agent in water becomes salting-out in aqueous mixtures of alcohols. The solvent properties, thus can be attuned by adjusting the amount of solvents and salts. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {aqueous alcohols, Diels-Alder reaction, endolexo ratios, salts}, issn = {0040-4020}, doi = {10.1016/j.tet.2005.06.010}, author = {Deshpande, Suvarna S. and Kumar, Anil} } @article { ISI:000292011000004, title = {Eutectic mixture-directed kinetics of Diels-Alder reaction}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {50}, number = {6}, year = {2011}, month = {JUN}, pages = {788-792}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

In the search for environmentally benign solvent media, a new class of solvents composed of mixtures of carbohydrates with urea or methylated urea has been noted to be effective in enhancing the reaction rates of a bimolecular organic reaction like the Diels-Alder reaction of cyclopentadiene with methyl acrylate. The viscosity of these media appears to be an important parameter in controlling the second order kinetics.

}, keywords = {carbohydrates, Cycloaddition, Diels-Alder reaction, Dimethylurea, kinetics, Reaction rates, solvent effects, Urea, viscosity}, issn = {0376-4710}, author = {Nagare, Amit S. and Kumar, Anil} } @article { ISI:000365445500001, title = {Water-promoted diels-alder reaction in quaternary ammonium salts}, journal = {Journal of Physical Organic Chemistry}, volume = {28}, number = {11}, year = {2015}, month = {NOV}, pages = {665-673}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

{Prevailing classification of salts based on their effect in solubility and stability of proteins in aqueous solution predicts that tetraalkylammonium salts, guanidinium chloride (GnCl), LiClO4 act as salting-in (S/I) and LiCl, NaCl act as salting-out (S/O) in aqueous conditions. In the same context the behaviour of GnCl, LiClO4 and LiCl are contradictory in polar solvents like ethylene glycol and formamide. In these solvents, expected salt effect shows just opposite nature from their usual expectation. However, in the aqueous solution salts like tetraalkylammonium halide (R4NX

}, keywords = {Delta G(solvation), Diels-Alder reaction, k(s), kinetic study, solubility, tetraalkylammonium salts, viscosity}, issn = {0894-3230}, doi = {10.1002/poc.3469}, author = {Nagare, Amit S. and Manna, Arpan and Sonawane, Pramod D. and Kumar, Anil} } @article { ISI:000381182700004, title = {Spectacular rate enhancement of the diels-alder reaction at the ionic liquid/n-hexane interface}, journal = {Chemphyschem}, volume = {17}, number = {13}, year = {2016}, month = {JUL}, pages = {1969-1972}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The use of the ionic liquid/n-hexane interface as a new class of reaction medium for the Diels-Alder reaction gives large rate enhancements of the order of 10(6) to 10(8) times and high stereoselectivity, as compared to homogeneous media. The rate enhancement is attributed to the H-bonding abilities and polarities of the ionic liquids, whereas the hydrophobicity of ionic liquids was considered to be the factor in controlling stereoselectivity.

}, keywords = {Diels-Alder reaction, Interfaces, ionic liquids, kinetics, stereoselectivity}, issn = {1439-4235}, doi = {10.1002/cphc.201600006}, author = {Beniwal, Vijay and Manna, Arpan and Kumar, Anil} } @article {46596, title = {Partially bio-based furyl-functionalized organosoluble poly(ether ether ketone)s}, journal = {Polymer International}, volume = {70}, year = {2021}, month = {AUG}, type = {Article}, abstract = {

A new series of partially bio-based (co)poly(ether ether ketone)s bearing pendent furyl groups was synthesized by nucleophilic aromatic substitution polycondensation of varying molar proportions of 4,4 {\textquoteleft}-(furan-2-ylmethylene)bis(2-methoxyphenol) and bisphenol-A with 4,4 {\textquoteleft}-difluorobenzophenone. The chemical structures, compositions and random nature of (co)poly(ether ether ketone)s were confirmed by NMR spectroscopy. Inherent viscosities and number-average molecular weights of the (co)poly(ether ether ketone)s were in the range 0.74-2.90 dL g(-1) and 33 500-46 300 g mol(-1), respectively, indicating the formation of reasonably high molecular weight polymers. (Co)poly(ether ether ketone)s were readily soluble in common organic solvents and could be cast into tough, transparent and flexible films from chloroform solutions. (Co)poly(ether ether ketone)s exhibited 10\% weight loss and glass transition temperatures in the range 429-464 and 152-156 degrees C, respectively. A representative copoly(ether ether ketone) was crosslinked with 1,1 {\textquoteleft}-(methylenedi-1,4-phenylene)bismaleimide via Diels-Alder reaction to form a crosslinked polymer which showed improved mechanical properties and was recycled twice without significant loss of mechanical properties. Diels-Alder/retro Diels-Alder reaction was demonstrated by studies of sol-gel transformation, solubility tests, DSC and stress-strain measurements. (c) 2020 Society of Chemical Industry

}, keywords = {aromatic poly(ether ether ketone)s, bio-based, crosslinking, Diels-Alder reaction, pendent furyl groups}, issn = {0959-8103}, doi = {10.1002/pi.6160}, author = {Kuhire, Sachin S. and Talanikar, Aniket A. and Tawade, V, Bhausaheb and Nagane, Samadhan S. and Wadgaonkar, Prakash P.} } @article {49827, title = {Post-functionalizable and reusable biobased polyhydroxyurethane adhesives with pendant furyl groups}, journal = {Reactive \& Functional Polymers}, volume = {216}, year = {2025}, month = {NOV}, pages = {106450}, type = {Article}, abstract = {

Polyurethane hot melt adhesives (PU-HMAs) are essential in various industries due to their fast-setting properties, strong adhesion, and versatility across a wide range of substrates. However, conventional fossil-based PUHMAs face significant challenges, including reliance on non-renewable resources, high environmental impact, and the use of hazardous isocyanates, which pose health and safety concerns. To address these issues, this study focuses on developing sustainable, high-performance PHU-HMAs containing pendant furyl groups for metal bonding. A series of adhesives were developed utilizing varying proportions of two biobased dicarbonates derived from lignin and sugar: one featuring a pendant furyl group (BGF-PF-DC) and another without the pendant group (BGF-DC), in conjunction with Priamine 1074. The study comprehensively examined the effects of these formulations on the physio-mechanical, thermal, and adhesive properties. The results demonstrated an impressive renewable carbon content of 89-90 \%, high adhesion strength of up to 9.27 MPa on aluminum and 9.43 MPa on stainless steel, excellent underwater adhesion, and outstanding reusability. Furthermore, the postmodifiability of pendant furyl in PHU6-PF100 was evaluated through cross-linking via the Diels-Alder reaction with bismaleimides (BMI). This study also examined the effects of these modifications on both the adhesive performance and thermal characteristics of the modified PHUs. However, the postmodified PHU/BMI network showed a decrease in adhesion but exhibited a higher glass transition temperature and improved adhesion stability at 50 degrees C compared to PHU6-PF100. This study emphasizes the sustainable and high-performance potential of PHU-based hot melt adhesives, establishing them as a viable alternative to traditional isocyanate-based systems. Furthermore, it introduces new opportunities for incorporating Diels-Alder (DA) chemistry into PHU adhesives, which allows for stable adhesion at elevated temperatures and broadens their applicability across various industries. Additionally, this research can serve as a foundation for future studies to investigate thermoreversibility in thermosetting PHUs, potentially expanding their range of applications even further.

}, keywords = {Biobased polyhydroxyurethanes, Diels-Alder reaction, Hot melt adhesives, Lap shear strength, Pendant furyl}, issn = {1381-5148}, doi = {10.1016/j.reactfunctpolym.2025.106450}, author = {Ghuge, Gorakh Hiraman and Nair, Kiran Sukumaran} }